Exhaust aftertreatment systems are typically provided to internal combustion engines to reduce undesired emissions in the exhaust stream exiting the engine. For example, a selective catalytic reduction (SCR) system may be utilized to convert NOx emissions into nitrogen and water, other catalytic converters such as a diesel oxidation catalyst (DOC) converter may be utilized to reduce hydrocarbon and carbon monoxide emissions, whilst a diesel particulate filter (DPF) may be utilized to reduce particulate emissions such as soot.
Many aftertreatment systems have temperature requirements that must be met for the system to operate effectively and so reduce emissions exiting a vehicle. In addition, aftertreatment systems may have additional temperature requirements to perform a regeneration of the aftertreatment system. As a result, there is often a need to increase the temperature of the aftertreatment system to a temperature at which operation or regeneration of the aftertreatment system is possible.
U.S. Publication 2011/0072782 discloses lowering the speed of an engine cooling fan associated with the aftertreatment system so that a temperature of the aftertreatment system increases and regeneration commences sooner.
Most aftertreatment systems are of limited efficacy prior to reaching its required temperature. Thus, it would be desirable to further reduce the time before operation or regeneration of the aftertreatment system commences.